The prior art vehicular rear-view mirror is either flat or spherical in shape, which provides narrowly viewing and blind spots. Accordingly, it is not helpful for safe driving.
To improve the prior art mirror, Chinese Utility Model No. 90206894.6, filed on May 26, 1990, disclosed a rear-view mirror for a vehicle in which the reflecting surface of the mirror is a convex shape, which is composed of a number of spherical surfaces of different curvature that are smoothly joined with each other and the curvature of the convex gradually increases from the top to the bottom i.e., the curvature of the upper portion of the reflecting surface is small or even zero while the curvature of the lower portion of the reflecting surface is large. Moreover, the curvature of the reflecting surface gradually increases along its lower portion as it is away from the body of the vehicle. This mirror is better than others since its viewing is broader and clear while the blind spots are eliminated. However, since the curvature of such a mirror increases only along the vertical direction and remains unchanged on the upper portion of the mirror along the horizontal direction, its viewing is not wide enough on the upper portion of the mirror.